Single Sign-On (SSO) and Microsoft Shared Point 2007

http://www.antionline.com/showthread.php?p=913053

I have got a main page called "staff portal" (main page for login) built in using Microsoft Share Point 2007 on a dedicated server , and we have got many other applications (done by developer) .

Each application on a dedicated server .

The application that we have got are based on the following technologies:
1. All are web based applications
2. Build either on .NET framework 1.1 or .NET Framework 2.0
3. SQL server as a database at the backend
4. None of them are active directory enabled .,,,,they need a lot of change to be active directory

But we have got one application in Java and DB2 at the backend, Iti is an active directory enabled and we need to have SSO for this application as well.

What will be the advise to use Single Sign On that comes with Microsoft Shared Point 2007 ? Is there any implication security ?